ACTIVELY EXPLOITED

CVE-2025-59287: Microsoft Windows Server Update Service (WSUS) Deserialization of Untrusted Data Vulnerability

Facts
VendorMicrosoft
ProductWindows
Actively exploitedYes
Added to CISA KEV24 Oct 2025
CISA federal deadline14 Nov 2025
Weakness (CWE)CWE-502

Required action (CISA's text)

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Description (NVD)

Microsoft Windows Server Update Service (WSUS) contains a deserialization of untrusted data vulnerability that allows for remote code execution.

SOURCES

Other Microsoft flaws

Data from NVD, CISA KEV, FIRST EPSS and vendor advisories. Updated 10 Nov 2026.